华南露天金属矿山土壤侵蚀特征及其对重金属迁移的驱动效应研究

There are adsorption and desorption between heavy metal pollutants and sediment, the sediment from soil erosion are transported with the migration of heavy metal, to have a research of the sediment from soil erosion and heavy metal contaminant transport and distribution laws, it will play a very important role to reveal the destruction of the chemical equilibrium by heavy metal from the accelerated erosion in mining area, and the control of soil heavy metal composite pollution in opencast metal mining area, restoration of the ecological function of contaminated soil in mining area, the coupling mechanism. This research is based on the present research situation of isotope tracer mechanism and artificial rainfall simulation, choose typical heavy metal pollution place in opencast metal mining area, south China, takes the migration process of heavy metal in typical region as the main research contents, takes soil and sediment in basic erosion unit in mining area as research object, by the main line of Pb-Cs isotopic composition through the research of isotopic composition and space distribution of Pb-Cs typical plot sediment source and sink of typical medium in mining area, according to discrimination index of Pb isotope, trace elements index and Cs isotope index, identify sediment source area, move process and analyze its characteristics; And under the support in rainfall simulation experiment hall, design soil erosion profile and the soil column simulation experiment, study the coupling mechanism of the soil heavy metal and sediment transport.

泥沙与重金属污染物之间具有吸附解吸作用，土壤侵蚀产生的泥沙输移伴随着重金属污染物迁移，研究土壤侵蚀泥沙以及重金属污染物的输移和分布规律、耦合作用机制，对于揭示矿区人为加速侵蚀导致的土壤重金属对地球化学平衡的影响，以及露天金属矿区控制土壤重金属复合污染、恢复矿区污染土壤的生态功能将起到重要作用。本研究依据同位素示踪机理及人工降雨模拟的研究现状，选择华南大型露天金属矿区典型重金属污染区切入，以矿区典型污染区域土壤重金属的迁移过程为主要研究内容，以矿区基本侵蚀单元内泥沙、土壤为研究对象，以Pb-Cs同位素组成为主线，通过研究矿区典型地块泥沙源与汇典型介质的Pb-Cs同位素组成与空间分布，结合Pb同位素判别指标、微量元素指标和Cs同位素指标，识别泥沙源区、输移过程并解析其特性；并在人工模拟降雨大厅的支持下，设计土壤侵蚀剖面和土柱模拟实验，研究泥沙输移与土壤重金属的耦合作用机制及驱动效应。

本项目主要应用同位素示踪技术，选择华南大型露天金属矿区典型重金属污染区为研究区域，以矿区典型污染区域土壤重金属的迁移过程为主要研究内容，以矿区基本侵蚀单元内泥沙与土壤为研究对象，通过研究矿区排土场土壤同位素与重金属组成与空间分布，结合同位素判别指标、微量元素指标和同位素指标，揭示了大宝山采矿区排土场土壤侵蚀特征，并应用环境核素示踪技术估算了该区域土壤侵蚀速率，分析了土壤重金属的迁移规律与污染特征，并分析了矿区下游河段的污染特征与来源，阐明了华南矿区土壤的主要特征，最后提出了应用环境核素示踪技术进行土壤侵蚀研究需要加强与深入的方面。